Molybdenum chloride alkylphenolates



United States Patent MOLYBDENUM CHLORIDE ALKYLPHENGLATEg Howard J. Matscn, Harvey, Ill., assignor, by mesne assignments, to Sinclair Research Inc, New York, N.Y., a corporation of Delaware No Drawing. Original application Apr. 4, 1958, Ser. No. 726,321, new Patent No. 3,047,500, dated .luly 31, 1962. Divided and this application Sept. 13, 1% Ser. No.

3 Claims.

the art that a lubricating oil such as a mere refined petroleum oil fraction is incapable of maintaining a lubricating film between engaged metallic surfaces where the unit load at the engaged surfaces exceeds a pressure of say 3,000 to 4,000 pounds per square inch. In various types of modern machinery, such as the hypoid gears used in motor vehicles, the engaging pressures between the gear teeth are so high that ordinary lubricating oils alone are incapable of properly lubricating them, the abnormally high pressures generally causing serious rupture of the oil film. To overcome this problem, special extreme pressure type lubricants have been developed. These lubricants are prepared by incorporating into a petroleum lubricating oil, or other suitable carrying agent, an additive ingredient which will form a lubricant film capable of withstanding these abnormally high pressures.

Ingredients of this character are known as extreme pressure (EP) ingredients. In addition, the American Petroleum Institute has adopted the designation Multipurpose -Type Gear Lubricants (A.P.I. Service GL4) to define gear lubricants that are compounded with higher performance additives whichprovide an advanced EP lubricant. Such a lubricant has an improved load carrying ability and other properties to protect hypoid gears in sustained high speed and/ or high torque service.

This invention provides an E? type lubricant which excels known lubricants in certain respects, and in a preferred embodiment, excels known lubricants in passing most standard EP type lubricant tests. The lubricant contains a novel oil-soluble molybdenum compound and in addition, a preferred embodiment also contains an oil-soluble organic sulfur compound. It is hypothesized that in the preferred embodiment the two additives re- 7 layers of sulfur atoms. The attractive forces in a single lamina, and between a single lamina and a metal surface, are relatively high due to the strength of the metal-tosulfur bond. However, the attractive forces between separate laminae are relatively low, due to the weakness Patented Aug. 24, 1965 ice of the sulfur-to-sulfur bond. Separate laminae will therefore tend to slide over each other, but will adhere tenaciously to metal surfaces.

Because M05 films are chemically inert and thermally stable, they are used to provide lubrication where conventional hydrocarbon or synthetic oils cannot be used. In order to be effective, however, the M08 film should form a solid and uniform bond with the metal surface. A bonded M03 film may be formed by hard mechanical rubbing, or by baking in the presence of a binder such as corn syrup. In contrast with the good EP properties of a bonded M08 film, M08 itself is not an effective extreme pressure, additive for lubricating oils. A basic difiiculty is its insolubility in natural and synthetic lubrieating fluids, causing it to eventually separate and settle in storage. Although M08 can be dispersed to some extent in lubricating oils, both mechanically and with dispersing agents, such dispersions do not approach bonded M08 film properties.

The novel molybdenum compounds of this invention have been found to give EP characteristics to lubricating oils whether or not sulfur is available in the oil. The novel molybdenum compound is the oil-soluble reaction product of molybdenum pentachloride and an oil-soluble alkyl phenol, for instance a polyalkyl or dialkyl phenol containing a total of at least 6 carbon atoms in the side chains. No chain of the phenol reactant will usually contain more than 18 carbon atoms and the total number of carbon atoms in the chains will ordinarily not be more than 24.

The reaction product which contains molybdenum dichloride alkyl phenolate can be manufactured by heating a mixture of the molybdenum pentachloride and phenol while removing HCl. The ingredients are preferably reacted while dissolved in a mutual solvent, such as toluene or xylene, under refluxing conditions of temperature and pressure.

a The major product of this reaction is the triphenolate, although minor amounts of the mono-, di-, or tetraphenolate may be present in the reaction product. The compound and scheme for the reaction of molybdenum pentachloride and diamyl phenol is as follows:

The triphenolate need not be separated fromthe other molybdenum phenolates of the reaction product for blending with an oleaginous liquid lubricating base.

The reaction product of molybdenum pentachloride and diamyl phenol is particularly preferred as the El additive of this invention because of its solubility in the lubricant base and its ease of manufacture from readily available materials. The theory analysis of molybdenum chloride tri (diamyl) phenolate is molybdenum, 11.1 percent; chlorine 8.2 percent The lubricating oil suitable for blending with the novel molybdenum compound of this invention can be a mineral lubricating oil fraction of the conventionally refined or solvent refined type. The mineral'lubricating oil fraction can be derived from a paraffinic, naphthenic or Mid-Continent crude and isof lubricating visocsity, e.g., from about 50 SUS at F. to 200 SUS at 210 F. The use of a low viscosity non-naphthenic 100 percent solvent refined neutral Mid-Continent base lubricating oil provides an EP lubricant having better low temperature pumpability. A blend of naphthenic and solvent'refined Mid-Continent lubricating oil bases may also be used with advantage.

. In addition to the distillate mineral lubricating oils men tioned, the various types of synthetic liquid oleaginous lubricating bases having comparable viscosities can also be employed as part or all of the lubricating base with the additive of this invention. Among the types of synthetic liquid oleaginous lubricating bases which can be employed are the oil-soluble high boiling high molecular weight aliphatic ethers, aromatic esters, aliphatic monoand dicarboxylic esters, phosphorus acid esters and halogenated aromatic compounds which possess lubricating properties and also have small change in viscosity for a given change in temperature. Of the various synthetic oleaginous compounds specified, those falling within the category of aliphatic dicarboxylic acid esters, and particularly the branched chain aliphatic diesters, such as di-Z-ethylhexyl sebacate, are preferred.

The molybdenum phenolate is blended with the lubricant base in proportions sufficient to give EP characteristics, usually about 0.1 to 10, preferably about 1 to 5 percent of phenolate in the final blend.

As has been mentioned, it has also been found that a lubricant composition containing available sulfur provides an additionally valuable EP lubricant. Sulfur is easily made available by blending with the lubricant base certain oil-soluble organic sulfur compounds. These compounds usually contain 6 to 30 carbon atoms, preferably 8 to 18 carbon atoms, in the molecule. The compounds which are preferred are sulfurized fatty oils such as sulfurized sperm oil, sulfurized rape seed oil, sulfurized cotton seed oil and sulfurized palm oil. Sulfurized olefins, such as a polyisobutylene or mixture of diand tri-isobutylenes which has been subjected to treatment first with sulfuryl chloride and then with sodium polysulfide, are also satisfactory for use with the novel EP ingredient of the invention. One such sulfurized olefin contains up to 46 percent sulfur by weight. A particularly effective material is sulfurized sperm oil which contains about 5 to 15 weight percent of combined sulfur. This additive can be employed in effective amounts of about 0.3 to 5 percent to contribute about 0.06 to 0.2 percent by weight of sulfur on the basis of the oleaginous liquid lubricant base of the composition. In general, the sulfur compound is used in the ranges of amounts indicated for the molybdenum phenolate. The compositions of this invention can contain other additive agents such as pour depressors, antifoam agents and viscosity index improvers.

The following example illustrates the preparation of the organic molybdenum reaction product: 46 gm. (0.168 mole) of MoCl were refluxed in 250 ml. toluene to dehydrate and remove occluded water. 117 gm. of diamyl phenol (0.5 mole) (Sharples, OH value=240) in 300 ml. of toluene were similarly dehydrated. After cooling to about 60 C. the MoCl -toluene mixture was combined with the diamyl phenol solution and the reaction mixture refluxed for a total of eleven hours, or until there was no further evolution of HCl gas. The reaction mixture was then filtered to remove some sludge and unreacted solids, and the bulk of the solvent was removed by distillation to 115 C. pot temperature at about 15 mm. mercury pressure. The product, which was estimated to contain about 10 percent residual solvent, gave the following analysis: molybdenum, 7.94%; chlorine, 4.14%. The product is a liquid of intense blue-violet color.

The effectiveness of this compound as an extreme pressure additive can be demonstrated in a variety of laboratory EP test machines. This in itself is unusual because frequently an additive which is shown to be advantageous by one machine is not shown to be similarly effective by another machine, even though both machines are recognized as extreme pressure lubricant testers. In view of the well-known hazards in trying to extrapolate EP performance in a single laboratory tester to performance under field service conditions, this versatile performance demonstrates a good probability of successful usage in a variety of practical applications.

The varied laboratory EP tests referred to were made on 2 weight percent blends of the additive contained in a 4 V.I. solvent refined neutral mineral lubricating oil of about 33 SUS viscosity at F.

The performance of the novel additive of the invention was compared with the performance of a standard additive which has been given a GL-4 rating. Details of the 4-Ball test can be found in Boerlage, Four-Ball Testing Apparatus for Extreme Pressure Lubricants, 136, Engineering, p. 46 (1933). The SAE test is described in the Journal of the Society of Automotive Engineers, July 1936, p. 293. The Falex Breakdown test is described in Lubrication Engineering, September 1946, pp. 1-9. Details of the Timken L-20 weedout test can be found in the US. Patent No. 2,715,612.

The results of these tests are given in Table I.

Table 1 Sample I II III IV Additive (wt. percent):

Molybdenum phenolate of example Sulfurized sperm oil High performance GL4 type multipurpose gear oil additivepolish polish Timken test:

Wear (mg) Condition of cup and block lines linespits * 100 lbs. at 200 r.p.m. and 200 F. for 16 hours.

These tests clearly demonstrate superior extreme pressure lubricant properties for the molybdenum phenolate containing blend, especially when in combination with an organic compound containing available or reactive sulfur. The latter composition permits a maximum load limit in both the SAE and Falex lubricant testers. Performance in the 4-ball test, which is frequently cited to demonstrate EP properties, is particularly outstanding. The Timken test shows that EP performance is obtained without any sacrifice of wear properties.

It is reasonable to theorize that the lubrication provided by this composition used in conjunction with a sulfur-containing additive is a result of a reaction between the sulfur and molybdenum additives, to form in situ a film of M08 on the worked surfaces. At the very least, the blend containing both sulfur and molybdenum combines the best characteristics of the separate blends, and in the case of the wear test, shows less wear than either of the individual additive blends.

Regardless of the mechanism, however, it is readily apparent from the data given in Table I that a molybdenum phenolate, blended alone or with an oil-soluble organic sulfur compound, provides an unusually effective EP composition. The degree of this improvement is indicated by comparison with the performance of other high performance multi-purpose type gear oil additives, which are recommended for use in both high torque and high speed operation.

I claim:

1. A molybdenum chloride diamyl phenolate product comprising, as its major constituent, molybdenum dichloride tri(diamyl phenolate) and also comprising minor amounts of a member selected from the group consisting of the corresponding mono, diand tetra(diamyl phenolates).

2. A molybdenum chloride alkyl phenolate product comprising, as its major constituent, molybdenum dichloride tri(alkyl phenolate) and also comprising minor amounts of a member selected from the group consisting of the corresponding mono, diand tetra(alkyl phenolates), each of said alkyl groups containing no more than 18 carbon atoms and the total alkyl carbon atoms in each alkyl phenolate moiety being 6 to 24, and said phenolate product being soluble in mineral lubricatingv oil.

3. A molybdenum chloride dialkyl phenolate product comprising, as its major constituent, molybdenum dichloride tri(dialkyl phenolate) and also comprising minor amounts of a member selected from the group consisting of the corresponding mono-, diand tetra(dialkyl phenolates), each of said alkyl groups containing no more than 18 carbon atoms and the total alkyl carbon atoms in each alkyl phenolate moiety being 6 to 24, and said phenolate being soluble in mineral lubricating oil.

References Cited by the Examiner UNITED STATES PATENTS TOBIAS E. LEVOW, Primary Examiner. 

2. A MOLYBDENUMCHLORIDE ALKYL PHENOLATE PRODUCT COMPRISING, AS ITS MAJOR CONSTITUENT, MOLYBDENUM DICHLORIDE RTI(ALKYL PHENOLATE) AND ALSO COMPRISING MINOR 